Determination of 10-hydroxystearic, 10-ketostearic, 8-hydroxypalmitic, and 8-ketopalmitic acids in milk fat by solid-phase extraction plus gas chromatography-mass spectrometry

Add time:09/06/2019    Source:sciencedirect.com

Fatty acids (FA) bearing oxygenated functions and present in esterified form in triacylglycerols are widespread in nature but very little is known about their occurrence in dairy products. A method based on gas chromatography (with flame ionization detector and mass spectrometry detectors), including the previous isolation of polar FA methyl esters by solid-phase extraction, was applied to quantify oxygenated FA in milk fat. Samples obtained from ewes and goats fed with a variety of oil sources were studied. Fatty acids identified were 8-ketopalmitic, 8-hydroxypalmitic, 10-ketostearic, and mainly 10-hydroxystearic acids. The highest levels of 10-ketostearic acid were obtained in milk from animals fed olive oil (up to 1.5%) and from those fed long-chain n-3 FA-enriched diets (0.5–1.0%). In all samples, 10-hydroxystearic acid, not reported so far in milk, was the second most abundant oxygenated FA (up to 0.8%). The high correlation obtained between contents of 10-ketostearic and 10-hydroxystearic acids would confirm the existence of a common pathway of formation in the rumen, whereas the presence of 8-ketopalmitate and 8-hydroxypalmitate could be putatively attributed to mechanisms of β-oxidation in the tissues. The influence of cis-9 C18:1 and trans-10 C18:1 as precursors of these compounds in milk and the metabolic pathways involved in their formation are discussed.

We also recommend Trading Suppliers and Manufacturers of 4-Ketostearic acid (cas 16694-30-7). Pls Click Website Link as below: cas 16694-30-7 suppliers

Prev:One-step and non-catalytic intramolecular redox reactions of conjugated all E-dienals to non-conjugated Z-enoic acids in subcritical water
Next:Chapter 4 - 12-Hydroxystearic Acid Oleogels)